The intra- and inter-rater reliability of manual muscle testing and a hand-held dynamometer for measuring wrist strength in symptomatic and asymptomatic subjects

Abstract

Objective The objective of this study was to assess the intra- and inter-rater reliability of manual muscle testing (MMT) and hand-held dynamometer (HHD) in the measurement of isometric wrist strength in asymptomatic and symptomatic (distal radius fractures [DRF] and non-specific wrist pain [NSWP]) populations. Method Thirty-nine adults participated in an intra session, repeat measure, crossover study design. MMT and HHD isometric wrist strength was tested in six standardized test positions by two raters. Results Poor-to-excellent intra- and inter-rater reliability with MMT was found in all patient populations (ICC = 0.04–1.00). Excellent intra-rater reliability with HHD in the DRF (ICC = 0.86–0.95) and NSWP (ICC = 0.92–0.97) populations and excellent inter-rater reliability in the asymptomatic (ICC = 0.77–0.93) and DRF (ICC = 0.82–0.95) populations. Fair to excellent intra-rater reliability with HHD was seen in the asymptomatic population (ICC = 0.71–0.94) and fair to excellent inter-rater reliability in the NSWP population (ICC = 0.59–0.90). Conclusion MMT is shown to have variable reliability when assessing isometric wrist strength and is insensitive to small strength changes. HHD has been shown to be an objective and reliable measure of isometric wrist strength in specific positions in asymptomatic, DRF and NSWP populations. Further studies are required to ensure adequate dynamometry stabilization and obtain an optimal testing procedure for these populations.